/*
NPlot - A charting library for .NET

LegendBase.cs
Copyright (C) 2003
Matt Howlett

Redistribution and use of NPlot or parts there-of in source and
binary forms, with or without modification, are permitted provided
that the following conditions are met:

1. Re-distributions in source form must retain at the head of each
   source file the above copyright notice, this list of conditions
   and the following disclaimer.

2. Any product ("the product") that makes use NPlot or parts 
   there-of must either:
  
    (a) allow any user of the product to obtain a complete machine-
        readable copy of the corresponding source code for the 
        product and the version of NPlot used for a charge no more
        than your cost of physically performing source distribution,
	on a medium customarily used for software interchange, or:

    (b) reproduce the following text in the documentation, about 
        box or other materials intended to be read by human users
        of the product that is provided to every human user of the
        product: 
   
              "This product includes software developed as 
              part of the NPlot library project available 
              from: http://www.nplot.com/" 

        The words "This product" may optionally be replace with 
        the actual name of the product.

------------------------------------------------------------------------

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

using System;
using System.Collections;
using System.Drawing;

namespace NPlot
{

	/// <summary>
	/// Provides functionality for drawing legends.
	/// </summary>
	/// <remarks>
	/// The class is quite closely tied to PlotSurface2D. 
	/// </remarks>
	public class LegendBase
	{

		/// <summary>
		/// Constructor.
		/// </summary>
		public LegendBase()
		{
			this.Font = new Font( new FontFamily("Arial"), 10, FontStyle.Regular, GraphicsUnit.Pixel );
			this.BackgroundColor = Color.White;
			this.BorderColor = Color.Black;
			this.TextColor = Color.Black;
			this.borderStyle_ = BorderType.Shadow;
			this.autoScaleText_ = false;
		}


		/// <summary>
		/// Get the bounding box of the rectangle.
		/// </summary>
		/// <param name="position">the position of the top left of the legend.</param>
		/// <param name="plots">Array of plot objects to appear in the legend.</param>
		/// <param name="scale">if the legend is set to scale, the amount to scale by.</param>>
		/// <returns></returns>
		/// <remarks>do implementation that doesn't call draw. Change xPos, yPos to PointF</remarks>
		public Rectangle GetBoundingBox( Point position, ArrayList plots, float scale )
		{
			System.Drawing.Bitmap b = new System.Drawing.Bitmap(1,1);
			Graphics g = Graphics.FromImage(b);
			return this.Draw( g, position, plots, scale );
		}


		/// <summary>
		/// Draw The legend
		/// </summary>
		/// <param name="g">The graphics surface on which to draw</param>
		/// <param name="position">The position of the top left of the axis.</param>
		/// <param name="plots">Array of plot objects to appear in the legend.</param>
		/// <param name="scale">if the legend is set to scale, the amount to scale by.</param>
		/// <returns>bounding box</returns>
		public Rectangle Draw( Graphics g, Point position, ArrayList plots, float scale )
		{

			// first of all determine the Font to use in the legend.
			Font textFont;
			if (this.AutoScaleText)
			{
				textFont = Utils.ScaleFont( this.font_, scale );
			}
			else
			{
				textFont = this.font_;
			}

			// determine max width and max height of label strings and
			// count the labels. 
			int labelCount = 0;
			int maxHt = 0;
			int maxWd = 0;
			int unnamedCount = 0;
			for (int i=0; i<plots.Count; ++i)
			{
				if (!(plots[i] is IPlot))
				{
					continue;
				}

				IPlot p = (IPlot)plots[i];

				if (!p.ShowInLegend)
				{
					continue;
				}
				string label = p.Label;
				if (label == "")
				{
					unnamedCount += 1;
					label = "Series " + unnamedCount.ToString();
				}
				SizeF labelSize = g.MeasureString( label, textFont );
				if ( labelSize.Height > maxHt )
				{
					maxHt = (int)labelSize.Height;
				}
				if ( labelSize.Width > maxWd )
				{
					maxWd = (int)labelSize.Width;
				}

				++labelCount;
			}

			bool extendingHorizontally = numberItemsHorizontally_ == -1;
			bool extendingVertically = numberItemsVertically_ == -1;


			// determine width in legend items count units.
			int widthInItemCount = 0;
			if (extendingVertically)
			{
				if (labelCount >= numberItemsHorizontally_)
				{
					widthInItemCount = numberItemsHorizontally_;
				}
				else
				{
					widthInItemCount = labelCount;
				}
			}
			else if (extendingHorizontally)
			{
				widthInItemCount = labelCount / numberItemsVertically_;
				if (labelCount % numberItemsVertically_ != 0)
					widthInItemCount += 1;
			}
			else
			{
				throw new NPlotException( "logic error in legend base" );
			}


			// determine height of legend in items count units.
			int heightInItemCount = 0;
			if (extendingHorizontally)
			{
				if (labelCount >= numberItemsVertically_)
				{
					heightInItemCount = numberItemsVertically_;
				}
				else
				{
					heightInItemCount = labelCount;
				}
			}
			else // extendingVertically
			{
				heightInItemCount = labelCount / numberItemsHorizontally_;
				if (labelCount % numberItemsHorizontally_ != 0)
					heightInItemCount += 1;
			}

			int lineLength = 20;
			int hSpacing = (int)(5.0f * scale);
			int vSpacing = (int)(3.0f * scale);
			int boxWidth = (int) ((float)widthInItemCount * (lineLength + maxWd + hSpacing * 2.0f ) + hSpacing); 
			int boxHeight = (int)((float)heightInItemCount * (maxHt + vSpacing) + vSpacing);

			int totalWidth = boxWidth;
			int totalHeight = boxHeight;

			// draw box around the legend.

			if ( this.BorderStyle == BorderType.Line )
			{
				g.FillRectangle( new SolidBrush( this.bgColor_ ), position.X, position.Y, boxWidth, boxHeight );
				g.DrawRectangle( new Pen( this.borderColor_ ), position.X, position.Y, boxWidth, boxHeight );
			}
			else if ( this.BorderStyle == BorderType.Shadow )
			{
				int offset = (int)(4.0f * scale);
				g.FillRectangle( new SolidBrush( Color.FromArgb(128, Color.Gray) ), position.X+offset, position.Y+offset, boxWidth, boxHeight );
				g.FillRectangle( new SolidBrush( this.bgColor_ ), position.X, position.Y, boxWidth, boxHeight );
				g.DrawRectangle( new Pen( this.borderColor_ ), position.X, position.Y, boxWidth, boxHeight );

				totalWidth += offset;
				totalHeight += offset;
			}

			/*
			   else if ( this.BorderStyle == BorderType.Curved )
			   {
				   // TODO. make this nice.
			   }
			*/

			else
			{
				// do nothing.
			}

			// now draw entries in box..
			labelCount = 0;
			unnamedCount = 0;

			int plotCount = -1;
			for (int i=0; i<plots.Count; ++i)
			{
				if (!(plots[i] is IPlot))
				{
					continue;
				}

				IPlot p = (IPlot)plots[i];

				if (!p.ShowInLegend)
				{
					continue;
				}

				plotCount += 1;

				int xpos, ypos;
				if (extendingVertically)
				{
					xpos = plotCount % numberItemsHorizontally_;
					ypos = plotCount / numberItemsHorizontally_;
				}
				else
				{
					xpos = plotCount / numberItemsVertically_;
					ypos = plotCount % numberItemsVertically_;
				}

				int lineXPos = (int)(position.X + hSpacing + xpos * (lineLength + maxWd + hSpacing * 2.0f));
				int lineYPos = (int)(position.Y + vSpacing + ypos * (vSpacing + maxHt));
				p.DrawInLegend( g, new Rectangle( lineXPos, lineYPos, lineLength, maxHt ) );
				
				int textXPos = lineXPos + hSpacing + lineLength;
				int textYPos = lineYPos;
				string label = p.Label;
				if (label == "")
				{
					unnamedCount += 1;
					label = "Series " + unnamedCount.ToString();
				}

				g.DrawString( label, textFont,
					new SolidBrush( this.textColor_ ), textXPos, textYPos );

				++labelCount;
			}
			return new Rectangle( position.X, position.Y, totalWidth, totalHeight );

		}


		/// <summary>
		/// The font used to draw text in the legend.
		/// </summary>
		public Font Font
		{
			get
			{
				return this.font_;
			}
			set
			{
				this.font_ = value;
			}
		}
		private Font font_;


		/// <summary>
		/// The color used to draw text in the legend.
		/// </summary>
		public Color TextColor
		{
			get
			{
				return this.textColor_;
			}
			set
			{
				this.textColor_ = value;
			}
		}
		Color textColor_;


		/// <summary>
		/// The background color of the legend.
		/// </summary>
		public Color BackgroundColor
		{
			get
			{
				return bgColor_;
			}
			set
			{
				bgColor_ = value;
			}
		}
		Color bgColor_;


		/// <summary>
		/// The color of the legend border.
		/// </summary>
		public Color BorderColor
		{
			get
			{
				return borderColor_;
			}
			set
			{
				borderColor_ = value;
			}
		}
		Color borderColor_;


		/// <summary>
		/// The types of legend borders (enum).
		/// </summary>
		public enum BorderType
		{
			/// <summary>
			/// No border.
			/// </summary>
			None = 0,
			/// <summary>
			/// Line border.
			/// </summary>
			Line = 1,
			/// <summary>
			/// Shaded border.
			/// </summary>
			Shadow = 2
			//Curved = 3
		}


		/// <summary>
		/// The border style to use for the legend.
		/// </summary>
		public Legend.BorderType BorderStyle
		{
			get
			{
				return borderStyle_;
			}
			set
			{
				borderStyle_ = value;
			}
		}
		private NPlot.Legend.BorderType borderStyle_;


		/// <summary>
		/// Whether or not to auto scale text in the legend according the physical
		/// dimensions of the plot surface.
		/// </summary>
		public bool AutoScaleText
		{
			get
			{
				return autoScaleText_;
			}
			set
			{
				autoScaleText_ = value;
			}
		}
		bool autoScaleText_;


		/// <summary>
		/// Setting this does two things. First of all, it sets the maximum number of 
		/// items in the legend vertically. Second of all, it makes the legend grow
		/// horizontally (as it must given this constraint).
		/// </summary>
		public int NumberItemsVertically
		{
			set
			{
				this.numberItemsVertically_ = value;
				this.numberItemsHorizontally_ = -1;
			}
		}
		int numberItemsVertically_ = -1;


		/// <summary>
		/// Setting this does two things. First of all, it sets the maximum number of 
		/// items in the legend horizontally. Second of all, it makes the legend grow
		/// vertically (as it must given this constraint).
		/// </summary>
		public int NumberItemsHorizontally
		{
			set
			{
				this.numberItemsHorizontally_ = value;
				this.numberItemsVertically_ = -1;
			}
		}
		int numberItemsHorizontally_ = 1;

	}

}
